The obesity epidemic in the United States threatens accuracy in diagnostic medical imaging studies - according to a 15-year retrospective study of all radiologic exams performed at the Massachusetts General Hospital (MGH) in Boston.
The study, presented this week at RSNA, reviewed radiology reports between 1989 and 2003 that were labeled "limited by body habitus" which translates to a reduction in quality of exam information as a result of patients' increased size.
Abdominal ultrasound was most often cited as limited by larger patients, with chest x-ray and abdominal computed tomography (CT) following as most frequently affected studies. Ultrasound is most negatively impacted since ultrasound waves must penetrate body tissues to produce quality diagnostic images, and therefore even slightly overweight patients may have compromised results. The quality of x-ray studies also can be reduced by inadequate penetration and film size.
Another issue involves weight restrictions inherent in equipment design, and the size of the area intended to accommodate the patient. For example, in most cases, quality CT images are possible in patients weighing up to 450 pounds and most MRI systems are capable of accommodating patients up to 350 pounds.
The negative aspects of lost revenues on a radiology department resulting from incomplete radiologic exams has more than tripled over the past eight years. Study authors calculated that direct costs of these unsatisfactory imaging results were approximately $100,000 in 2003 as compared to $28,000 in 1995.
Implications include the need to modify equipment design and technology to facilitate quality diagnostic exams for larger patients. Additionally, radiologists should optimize current protocols to improve accuracy in imaging studies for current obese patients.